Organic light emitting diode device (further also referred to as OLED devices) typically comprises a cathode, an anode, an emissive layer and a conductive layer. These parts can be positioned on a substrate. The emissive and conductive layers are manufactured of organic material that can conduct an electric current. When a voltage is applied across the cathode and anode, electrons travel from the cathode towards the anode. Furthermore, holes are created in the conductive layer at the anode side and propagate towards the cathode. When electrons and holes recombine, photons are created and emitted from the OLED device.
OLED devices are in many ways considered as the future in various lighting applications. They may, for instance, be used to create ambient lighting. Full 2-dimensional grey-level pictures may be patterned in a single OLED device, while maintaining all intrinsic advantages of OLED devices, for instance, being appealing, being a diffuse area light source and so on.
An example of patterned OLED devices is presented in the US 2004/0119028 document. In these known OLED devices an encapsulated small molecule OLED device has been irradiated with a laser beam having a wavelength in the infrared spectrum, decreasing the electroluminescence in the areas exposed to the laser.
A disadvantage of these known patterned OLED devices is that the patterned part of the OLED device is not clearly visible when the device is not in operation.